Alex Thomas Messina

Terrigenous sediment dynamics in a small, tropical, fringing-reef embayment

2016

Department of Marine and Wildlife Resources of American Samoa

"Anthropogenic watershed disturbance by industry, agriculture, deforestation, roads, and urbanization alters the timing, composition, and mass of sediment loads to coral reefs, causing enhanced sediment stress on corals near the outlets of impacted watersheds (Syvitski et al., 2005; West and van Woesik, 2001). Few studies have developed an integrated understanding of sediment sources, transport processes, and deposition in small, reef-fringed embayments (Bartley et al., 2014; Draut et al., 2009; Wolanski et al., 2003) and many are outside the scope of local environmental managers in remote islands like at the study site, Tutuila, American Samoa. Ridge-to-Reef studies on sediment dynamics have three general components, which are reflected in the three chapter structure of this dissertation: watershed inputs, hydrodynamic circulation over the reef, and how they interact to govern spatiotemporal distribution of sediment accumulation on the reef. This dissertation provides an example of how a scientific, process-oriented Ridge to Reef study of sediment dynamics can answer critical scientific questions about the source, transport, and fate of sediment in the near-shore environment, and how answers to the scientific questions can support local coral management."

FY13; CRCP Project ID: 198; Project Title: Domestic Coral Reef Conservation Grant Programs; Principal Investigator: Kristine Bucchianeri; CRCP Grant Number: NA13NOS4820013